Add create_handle support to cirrus fb. Without this, screenshot tool
in chromium OS can't work.
Signed-off-by: NLepton Wu <ytht.net@gmail.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20171108185537.56167-1-ytht.net@gmail.comSigned-off-by: NGerd Hoffmann <kraxel@redhat.com>